add .envrc

This can be used as an example on how to integrate with direnv.

Author: zimbatm

.envrc

@@ -0,0 +1,17 @@
+#!/usr/bin/env bash
+# ^ added for shellcheck and file-type detection
+
+# Watch all of these files for change
+watch_dir modules
+watch_dir nix
+watch_file devshell.toml
+
+# Store the shell symlink in the direnv layout directory
+out_link="$(direnv_layout_dir)"/devshell
+
+# Build the devshell environment
+nix-build shell.nix --out-link "$out_link"
+
+# Load the devshell
+# shellcheck disable=SC1090
+source "$out_link"